Can I pre-sanitize a keg?

I have two kegs and I've only kegged two beers, so far. After the first keg went empty, I thoroughly cleaned and rinsed it. Then, I disassembled it and soaked the small pieces in StarSan, re-assembled, sloshed more StarSan around in the keg and pumped it out through a picnic tap. At this point, I was left with a sanitized, pressurized keg, which I left sealed and put in my basement. Assuming I cleaned and sanitized properly, can I rack my next beer directly into this keg? Is there any reason to re-sanitize, like mold or other nasties that could develop in the 4 weeks it's been sitting?

Starsan doesn't actually kill EVERYTHING, just 99.9% of everything. The stuff that's left COULD grow, even in a CO2 atmosphere, (we get infections, right??, there is such thing as anaerobic buggies), but usually it won't grow much.

As a happy compromise, I keep about 3/4 of a gallon of starsan in my kegs. I shake it around and then dump it out on kegging day. I figure that will kill anything that could have tried to grow in storage.

Thanks, shortyjacobs. Keeping some sanitizer in the keg is a good idea. I'll give that a shot next time. This time, I think I'll re-sanitize, just in case.

Make sure you hit the outside parts with spray of starsan too. Inside should be good to go though if you keep a bit in there as shorty suggested.